main air bleed enlargement

[Jeff1]

Hello All :
     I'm working on the following 7027211 Carb installed on big block chevy  396 30 over 10 to 1 with an XE 276 roller cam 110LSA. Timing 18  int 35 total plus 8 degrees of ported vac advance. I'm using Recipe #2.  The item i have a lack of understanding of is Main air bleeds. Have now in both main body and air horn a size of .048. the recipe calls for .070 in both. It also calls for the lower idle air bleed to be at ,070 my as best i can measure is .052. I'm glad to do it just don't understand why. I've read the book and I'm just trying to understand. Can someone help an old fool out?  all other specs are as outlined in the recipe. Thanks to all and thanks to Cliff for helping me dust off all this stuff after 40 years.
Jeff

[Cliff Ruggles]

On that carb I would leave all the airbleeds at the stock sizes.  It is pre-emission and will put down more fuel everyplace with the smaller bleeds.

It will still need some help to work well with that cam in a 396 at 10 to 1 compression.  Most likely it will need a bit more idle fuel, and some bypass air as well. 

I would get one of our kits, and we'll spec out tuning parts at the same time, jets, metering rods, PP spring, etc.....Cliff

[Jeff1]

Thanks Cliff.  I already have your parts. .135 needle and seat  37 down tubes
.052 dcr ,accelerator pump. 71 jets , orange pp spring. Primary rods 44B
I was just trying to grasp an understanding of what I was accomplishing wt opening them
Up.  I will leave them stock for now.   Thanks. And thanks for the courtesy of the phone call.
Jeff